Ink fountain



Jan, 7, 1964 H. D. WARD, JR., ETAL 3,

INK FOUNTAIN Filed Dec. 23, 1959 3 Sheets-Sheet 1 v if. INVENTORS. HEN/e) D. M420 Je.

BOYCE c. DEA/7' y cHaeLss D- MITCH/E Jan. 7, 1964 H. D. WARD, JR., ETAL 3,116,688

INK FOUNTAIN 5 Sheets-Sheet 2 Filed Dec. 23, 1959 INVENTORS. MED J2,

BOYCE C. DENT CHAR D- Al/TCH/E Jan. 7, 1964 Filed Dec. 23, 1959 H. D. WARD, JR., ETAL INK FOUNTAIN 3 Sheets-Sheet 3 50? Y C H14 INVENTO v HEX/EV 0. 144720.

C- DEA/7' E5 0. MITCH/E United States Patent ()filice hllligdf d Patented Jan. 7, lbfid 3,116,683 WK FUUNTAlN Henry D. Ward, lira, Timoninm, Charles E). Nitchie, Towson, and Boyce 6. Dent, Timonium, Md, assignors to Koppers Company, line, a corporation of Delaware Filed Dec. 23, 1959, Ser. No. 861,614 8 Claims. (til. lil135tl) This invention relates to ink fountains employed in printin apparatus and more particularly to an ink fountain of the type having a rotatable fountain roller and a fountain blade for metering the ink applied to the roll.

it is an object of the present invention to provide an improved ink fountain structure for facilitating the distribution of ink on the fountain roll.

it is a further obiect to provide an improved ink fountain incorporating therein a novel means for adjusting the fountain blade relative to the roll so as to permit rapid changing of the ink distribution along the length of the roll.

It is another object to provide an ink fountain having means for maintaining the pressure exerted by the fountain blade against the fountain roll so that damage and wear to the roll are minimized.

It is still another object to provide an improved ink fountain employing a novel arrangement for simplifying the cleaning of the ink fountain and the various components.

in carrying out the invention, the ink fountain comprises generally a body member having an inclined surface on which there is mounted a blade supporting member and fixedly secured a pair of spaced end plates. The end plates support a rotatable ink fountain roll of which the longitudinal axis is arranged lengthwise of the blade supporting member. Mounted on the blade supporting member is a flexible fountain blade having a portion adjacent the fountain roll movable relative to the supporting member such that the terminal edge of the blade may be flexed into and out of selective engagement along the length of the roll. The flexing of the blade is accomplished by a combined pneumatic and mechanical means of which the pneumatic means is employed primarily to maintain predetermined maximum engagement pressure of the blade along the length of the roll, and the mechanical means is employed to selectively adjust the spacing of the blade edge along the span of the roll.

For purpose of facilitating the cleaning of the fountain, there is employed a means for sliding the blade supporting member and accordingly the blade mounted thereon normal to the longitudinal axis of the fountain roll toward and away from the latter.

Further objects and features will hereinafter appear.

in the drawings:

PEG. 1 is a partial plan view of a printing press illustrating an ink fountain embodying the present invention and its relationship to a doctor roll.

FIG. 2 is a sectional view taken substantially along the line llll of H6. 1.

FIG. 3 is a sectional view taken substantially along the line llllll of FIG. 2.

FIG. 4 is a sectional view taken substantially along that line lV-lV of PEG. 3 showing the gear drive for sliding the blade support transversely of the ink fountain roll.

FIG. 5 is a perspective view of the pivot blocks employed to flex the fountain blade.

H6. 6 is an elevational sectional view of a second embodiment of the invention.

FIG. 7 is a partial sectional view taken substantially along the line Vii-VII of MG. 6 showing the gear drive for sliding the blade support transversely of the ink roll.

Referring now to the drawings, there is illustrated an ink fountain generally designated as 10 comprising an ink fountain roll 11 and an ink reservoir 13. Located adiacent the ink fountain roll 11 is a doctor roll 15 which as shown is mounted in fixed spaced relation to said fountain roll 11. It is to be understood, however, that the doctor roll 15 may be of the type which is supported to oscillate so as to transfer ink from the fountain roll to the printing roll (not shown) in the well known manner.

The ink fountain includes a base member 17 which is supported in a manner to be more fully explained hereinafter on the side frame members 19 of the printing press. The upper surface 21 of the base member 17 is inclined and slidably supports thereon by means of transverse dovetailed grooves 18 a blade supporting mernber 23 which extends the full length of the fountain roll ll. The blade supporting member '33 may be formed of two rectangular sections which are assembled along their length by means of screws 24.

Also secured to the base member 17 and arranged so as to embrace snugly the shaft ends 25 and form a substantially ink tight fit at the shoulders 27 of the fountain roll 11 and thereby seal the ends of the fountain roll 11 so as to prevent the ink held Within the reservoir 35 from flowing onto the shaft ends are spaced end plates 29. It is to be noted that the end plates 29 are mounted on the base member 17 and also support the fountain roll ill so as to form a unitary device which may be attached as such to the frame 19 of the printing ress when assembled.

The fountain roll 11 is rotated by the usual well known mechanism (not shown), such as a pawl and ratchet, in timed relationship with the doctor roll 15.

A flexible blade 33 is secured to the top of the blade supporting member 23 as by screws 31 countersunk into the blade and the member 23. The blade 33 overhangs the support 23 adiacent the fountain roll 11 such that the overhanging portion and the terminal edge 35 may be flexed upwardly into and downwardly out of contacting engagement with the fountain roll 11.

To accomplish the movement of the blade 33 into and out of contact with the roll 11, in accordance with the present invention, there is provided a novel camming mechanism which as shown includes a plurality of sideby-side pivot blocks 37 disposed in a longitudinal groove 38. The pivot blocks 3'7 are mounted on a common pivot shaft 39 extending parallel to the longitudinal axis of the fountain roll ll. As shown in FIG. 5, each of the blocks 3'7 is formed with a camming node 41 intermediate the side walls thereof so that the node 41 engages the underside of the flexible blade 33 at spaced points along its length.

The blade 33 is flexed by an inflatable hose 43 which is disposed within the groove 38 so that upon expansion thereof as viewed in PEG. 2, a moment is exerted on the pivot blocks 37 and the nodes ll are turned counterclockwise thereby exerting a moment on blade 33 to flex the blade edge 35 into contact with the fountain roll fl. When the hose 43 is contracted, as by the release of fluid pressure therefrom, the pivot block 37 turns clockwise under the force exerted by flexed blade 33 because of its propensity to return to its fiat unstressed position and blade edge 35 is withdrawn from contact with the roll 11. The hose 43 is connected to a suitable source of fluid supply (not shown) by way of inlet 45. It is to be noted that the maximum pressure exerted by the fountain blade 33 against the roll ltll is substantially equal to the predetermined force of pressure exerted on the pivot block 37 by the tube 43. fence, the amount of pressure within the tube is used to regulate thte contact pressure of the blade edge. The pressures applied are selected such that the blade edge firmly seals against the roll ll while at the same time not causing damage thereto. Controlling the force by the application of fluid pressure exerted by the blade against the roll is of significance since the maximum contacting pressure exerted by the blade edge 35 will be equal along the entire length of the roll 11. Heretofore, difficulty has been encountered by the positive mechanical devices formerly employed which required individual adjustment along the length of the roll. Such individual adjustment oftentimes resulted in application of localized excessive pressures creating forces of such magnitude that the fountain roll was distorted. This distortion resulted in poor ink transfer to the printing roll by way of the doctor roll, and under some circumstances, in permanent damage to the fountain blade or fountain roll itself.

As is well known in the art, the fountain roll is usually provided with predetermined thicknesses of ink at selected spans along the length. The locations of these spans of ink are determined by location of the type to be printed on the printing roll. To this end, the fountain blade must be selectively spaced from the periphery of the roll at the desired spans so that the ink may be transferred to the printing roll only at the desired locations. In accordance with the present invention, the spacing is accomplished by providing each of the pivot blocks 37 with a thumb screw arrangement which cooperates with a camming surface 46 formed on each of the blocks 37. The thumb screw arrangement comprises a camming rod 47 freely slidably disposed in a bore 48 extending transversely to the pivot axis of the block 37. One end of the rod 47 engages the camnn'ng surface 46 while th other end is in engagment with a thumb screw 4-9 threaded into the blade supporting member 23. The camming surface 46 and the thumb screw arrangement are arranged so that upon turning the thumb screw inwardly, the block 37 is turned clockwise exerting a moment counter to the moment exerted by the force of the fluid pressure in inflated hose 43 about pivot shaft 39 such that the hose 43 yields. In this manner, the block 37 is depressed in the hose 43 and the node 41. moves downwardly within the slot 38 a corresponding amount. The flexible fountain blade 33, because of its inherent spring action returns toward the supporting member such that the blade edge 35 is spaced from the fountain roll at those points in which the nodes 431 have been lowered into the slot 38. In this manner, by selectively depressing the nodes 31 along the length of the blade 33, the spacing of the blade edge along the ink fountain roll 11 to achieve the desired ink spans may be readily accomplished.

By the present invention, there is incorporated into the ink fountain it a novel means for cleaning the roll 11 after it has been used. This is accomplished by a gear drive means for sliding the blade supporting member 23 and accordingly the blade 33 transversely toward and away from the fountain roll 1 1. As shown, the drive means comprises a hand wheel 51 attached to one end of a shaft 53 which is suitably journaled lengthwise at opposite ends of the base member 17. Fast on the shaft 53 in the spaces defined by the webs d beneath both end plates 29 are worms 5'7 which are held against lengthwise movement of the shaft 53 by collars 6d. Meshing with the worms 57 are gears 61 fixed to the lower ends of the spindles 63 journaled at each end of the base 17. Secured to the upper end of the spindles 63 are pinions 65 which are accommodated within cutout portions 67 formed in the end plates 29. Meshing with the pinions 65 and accommodated within transverse grooves 69 communicating with the cutout portions 67 are racks 71 which are secured as by welding to each end of the blade supporting member 23.

It is apparent from the foregoing that upon turning the hand wheel 51, the worms 57 meshing with the gears 61 is operative to rotate the gears 61 and the pinions 65 so as to move the racks 71. In this manner, the blade supporting member 23 and accordingly the blade 33 may be 4 moved either toward or away from the axis of the fountain roll 11, remaining parallel thereto.

In order to clean the ink fountain, the hose 43 is retained inflated so that the blade edge 35 remains in full pressure engagement with the rotating fountain roll ll. The hand wheel is then turned so as to advance the blade supporting member 23. The blade 33, of course, is forced downward towards the blade supporting member 23 and remains in engagement with the roll 11 since the pressure exerted by the inflated tube holds the blade 33 in scraping engagement with the fountain roll ill. At the same time that the blade 33 is forced against the force exerted by the hose 43, because face 46 moves clockwise under such conditions, the pressure exerted by the adjustment screws 49 on the pivot blocks 37 is released such that no matter what the relative positions of the screws 49 were prior to cleaning, the pressure of the blade along the entire span of the fountain roll is equal under scraping conditions. The fountain roll 11 is rotated counterclockwise with the blade 33 in scraping contact therewith, which prevents any ink flow from the reservoir 13 onto the roll 11. As ink flows from a wet roll onto drier roll, the doctor roll 15 and each subsequent roll located between the fountain roll and the printing bed (not shown) are cleaned by the dry fountain roll 11. In this manner, a substantial amount of ink which would otherwise be wasted is returned to the ink reservoir 13.

When the fountain roll 11 has cleaned all the subsequent rolls, the reservoir '13 is drained and the fluid pressure in the inflatable tube 43 is released. Thereafter the handwheel 51 is turned to move the blade supporting member 23 and the blade 33 back away from the fountain roll 11 so that there is a gap between the blade edge 35 and the roll 11. The ink left on the blade edge 35 and the corresponding line of ink remaining on the roll 11 may then be wiped away. After cleaning, the blade supporting member 23 is returned to its operating posi* tion and the hose is inflated such that the blade edge 35 is again in pressure engagement with the fountain roll ll ll.

As a further feature of the present invention, there is provided a means for selectively spacing the fountain roll from the doctor roll 15. To this end, as shown in FIG. 2, there is threaded into the base 17 of the ink fountain It] a stud 73 having an elongate head 75' provided with an opening 77 loosely accommodating a bolt 79 so as to permit turning of the latter within the opening 77. The bolt 79 is threaded into the frame member 19 and held against axial movement within the opening 77 between the bolt head 8t) and lock nut assembly forming a stationary collar 32 threaded on the bolt 79. To permit relative adjustment of the ink fountain assembly, the flanges 78 of the base 17 adjacent the frame members 19 are provided with elongate openings 81 so that upon loosening of the bolts 83 securing the base 17 to the frame members 19, the ink assembly may be moved either toward or away from the doctor roll 15. Hence, when the bolts are loosened, the bolt 79 may be turned in the desired direction to effect the desired spacing from the fountain roll to the doctor roll because the entire fountain assembly id is moved by way of the stud 73 which is eld between the head 8t} and collar 82 on the bolt 79.

Referring now to FIGS. 6 and 7, there is illustrated a second embodiment of the invention in which like parts are designated alike.

The ink fountain 1% comprises generally, as the first embodiment, a fountain roll 11 and an ink reservoir 13. The ink reservoir 13 includes a base member 111 mounted on the side frame members 19 by way of flanges 113 in front of the doctor roll 15. Spaced end plates 117 are mounted on an upper inclined surface 115 of the base member 111 and arranged so as to embrace snugly the shaft end adjacent the shoulder of the fountain roll 11 to support the latter and form an ink tight seal. It is to be noticed that with such construction, the ink reservoir and the fountain roll may be assembled apart from.

the printing press and applied as a unitary device. As shown, the ink fountain 100, is secured to the frame members 19 in a stationary manner, by bolts 1-14 through flanges 113. However, it is to be understood that provisions for adjustment of the ink fountain Hit and the fountain roll 11 relative the doctor roll 15 may be as shown and described in connection with the first embodiment of the invention.

A blade supporting member 12-1 is slidably supported by means of a dovetail groove 118 on the upper inclined surface 115 between the inside walls of the end plates ll? such that it extends along the full length of the fountain roll ll. The blade supporting member 121 may be formed of two members 121a and 121k which are held in fixed spaced relationship by rack 125" located within an elongated opening 127 formed in the inner wall of the end plates 1117.

A flexible blade 12) is secured as by countersunk screws 131 to the member 1211a. The blade is arranged to extend the full length of the fountain roll if and is of sufflcient width such that its free terminal edge 132 overhangs the wall of the member lZlb.

For urging the edge 132 into engagement with the mountain roll 11, an inflatable hose 133 is seated within a lon itudinal groove 135 formed in the member 1215. The hose 13 3 is arranged such that upon inflation thereof, the blade 12% is flexed upwardly under the moment exerted thereon by hose 133 urging blade edge 132 into pressure engagement with the roll 11 and upon contraction or deflation, the blade edge 132 moves out of engagement with the roll as explained in connection with the previous embodiment. The fluid hose 133 is connected by way of fitting 137 to a suitable source of fluid not shown. To control the contact pressure of the blade edge 132 with the roll ii, the fluid pressure within the hose is maintained at value below that at which the flexed blade edge causes damage to the fountain roll.

For selectively spacing the blade edge 132 away from the roll lil so as to form spaced ink spans along the length of the roll, there is provided a plurality of lengthwise spaced blade retracting members 139. Each of the retracting members 139 includes a rod Mil fixed as by welding to the underside of the blade 12? and dis posed within the space between the members 121a and 12112. Extending transversely through the lower end of the rod 141 is a pin 143 which is arranged such that the ends projecting beyond the periphery of the rod 141 are engaged by bifurcated arms 14d of a pivot block 145. The pivot block M5 is disposed in a slot 147 formed in the front wall of the member 12in and is rotatably supported by a longitudinal extending rod common to each of the retracting members 13%. The wall 152i between the arms 144 is relieved at an angle to permit turning of pivot block 145 toward the rod 141. A cumming face 153 formed on the rear wall of the block 145 is engaged by one end 155 of a camming rod 157 which is freely slidably disposed within a transverse bore 159. The other end of the rod is engageable with the thumb screw 49 threaded into the end Wall of the member 121a. Turning of the thumb screw inwardly is effective to move the carmning rod 157 forwardly such that it bears against the camming surface 153 and urges the pivot block 145 and, accordingly, the bifurcated arms Add clockwise. in this manner, the arms 114A- engaging the pin 143 pull the rod 141 downwardly exerting a moment on blade 129 counter to the moment exerted thereon by hose 133. Hence, the blade 129 fixed to pin Ml flexes downwardly and is depressed into the inflated tube against the force exerted by the fluid pressure. It is clear, of course, that the distance that the blade is deflected into the tube will determine the spacing of the blade edge 13?. from the roll it and this gap in turn is determined by the angle through which the pivot block 145 has been turned by the thumb screw 49 and cumming rod 157.

As described in connection with the first embodiment, the required spans or gapping along the fountain roll is achieved by selectively adjusting the thumb screws The embodiment illustrated in FIGS. 6 and 7 is also provided with a means for sliding the blade supporting member 121 and th reby the blade 12% transversely of the roll 11. This is accomplished by gear drives including a shaft 163 which is suitably iournaled on the underside of the base ill and has been fixed thereto beneath each of the end plates 1T1? and worms 165 which mesh with gears 16? fixed on the lower ends of a spindle 169. Pinions 1'71 fixed on the upper ends of the spindles mesh with the racks fixed to opposite ends of the blade supporting member 121. The hand wheel 51 is attached to one end of the shaft 163. As in the embodiment of FIGS. l5, the Worm gears may be held against lengthwise movement along the shaft in?) by collars not shown.

To clean the ink fountain ltlfl and the subsequent rolls (not shown), hand wheel 523. is rotated so that the worm gears 165 drive the blade supporting member 12?; forward by way of the gears 167, 171, and racks 125, of which the latter are fixed to member 121. The tube 153 is maintained inflated such that the blade edge 132 firmly engages the roll along the entire length at an equal pressure. In this connection, it is to be noted that when the member 121 is moved forward, the blade 129 is depressed into the tube 3.33. This causes the rod 141 to be lowered such that the pivot member turns clockwise. Hence, the camming rod 157 and thumb screws adjustably positioning the latter are released from having any influence on the position of the edge 132. In this manner, the scraping pressure of the blade edge is dependent only on the fluid pressure within the inflatable hose 133, which pressure is uniform along the entire length of the blade. Accordingly, the blade edge contacting pressure is equal along the length of the roll if.

After the rolls have been cleared, the fluid pressure within the inflatable hose is released and the hand wheel is turned to retract the blade so that the fountain parts may be wiped clean. After cleaning, the blade 129 is returned to its operating position and the hose is again inflated to achieve the desired contacting pressure.

What is claimed is:

1. In an ink fountain for a printing press having a rotatable fountain roll, an ink reservoir comprising a blade support, a flexible blade mounted on said support parallel to said roll and having an edge in close proximity to said roll, means for flexing said edge of said blade into direct contact with said roll lengthwise thereof, said flexing means comprising a plurality of side-by-side pivot blocks each of which has a blade cumming surface en gaging the under side of said blade, inflatable means engagin said pivot block for urging said camming surfaces into pressing engagement with said blade when said inflatable means is inflated so that said edge of said blade contacts the surface of said roll, and adjustable means engaging each of said pivot locks for selectively depressing said pivot blocks into said inflatable means so as to withdraw said blade edge from contact with said surface of said roll at desired spans along the length thereof.

2. In an ink fountain for a printing press having a rotatable fountain roll, an ink reservoir comprising a blade support located adjacent said fountain roll, a single flexible blade mounted on said support with an edge of said blade parallel to and closely spaced from the surface of said fountain roll, means mounted below said blade on said support for exerting a variable yieldable force urging said edge of said blade along the length thereof into engagement with said surface of said fountain roll lengthwise thereof and means mounted below said blade on said support for applying a non-yieldable counterforce to offset said yieldable force in part at a position along the length of said blade to selectively withdraw the portion of said blade edge adjacent said position from contact with said fountain roll.

3. In an ink fountain for a printing press having a rotatable fountain roll, an ink reservoir comprising a blade support located adjacent said fountain roll, a single flexible blade mounted on said support with an edge of said blade parallel to and closely spaced from said fountain roll, first means mounted on said support below and contiguous with said blade for exerting a variable resilient force urging said edge of said blade along the length thereof into direct contact with said fountain roll lengthwise thereof and means pivotally mounted on said support below said blade for selectively transmitting a non-resilient force counter to said resilient force to offset said resilient force in part whereby a portion of said blade edge is withdrawn from direct contact with said fountain roll.

4. In an ink fountain for a printing press having a rotatable fountain roll, an ink reservoir comprising a blade support located adjacent said fountain roll, a single flexible blade mounted on said support with an edge of said blade parallel to and closely spaced from the surface of said fountain roll, inflatable means mounted below said blade on said support for exerting a variable resilient force urging said edge of said blade along the length thereof into direct contact with said surface of said fountain roll lengthwise thereof and means mounted below said blade on said support for applying non-resilient counterforces to offset in part said resilient force at selected positions along the length of blade to selectively withdraw ortions of said blade edge adjacent said positions from direct contact with fountain roll.

5. in an ink fountain for a printing press having a rotatable fountain roll, an ink reservoir comprising a blade support located adjacent said fountain roll, a single flexible blade mounted on said support with an edge of said blade parallel to and closely spaced from said fountain roll, means contiguous with and below said blade for exerting a variable resilient force urging said edge of said blade along the length thereof into direct contact with said fountain roll lengthwise thereof and camming means located below said blade at spaced positions along the length of said blade for selectively transmittin g non-resilient forces counter to said resilient forces to offset said resilient forces in part at said positions whereby portions of said blade edge adjacent said positions are withdrawn from direct contact with said fountain roll.

6. In an ink fountain for a printing press having a rotatable fountain roll, an ink reservoir comprising a blade support located adjacent said fountain roll, a single flexible blade mounted on said support with an edge of said blade parallel to and closely space from the surface of said fountain roll, inflatable means mounted below said blade on said support for exerting a variable yieldable force urging said edge of said blade along the length thereof upwardly into direct contact with said surface of said fountain roll lengthwise thereof and camrning means located below said blade at spaced positions along the length of said blade for selectively transmitting nonyieldable counterforces to offset said yieldable force in part at said positions to selectively withdraw portions of said blade edge adjacent said positions from direct contact with said fountain roll.

7. In an ink fountain for a printing press having a base, an ink reservoir mounted on said base, a rotatable fountain roll journaled in opposing end walls of said reservoir, said ink reservoir comprising a blade support located adjacent said fountain roll, a single flexible blade mounted on said blade support with an edge of said blade disposed proximate to the surface of said fountain roll and parallel to the central axis thereof, inflatable means mounted on said blade support below and contiguous with said blade for exerting a controllable resilient force against me lower face of said blade along the length thereof to urge said edge into direct contact with said fountain roll lengthwise thereof, carnrning means located below said blade at spaced positions along the length thereof for selectively applying non-resi ent forces to said blade opposite in direction to said res nt force to offset said resilient force in part at said positions whereby portions of said blade edge adjacent said positions are withdrawn from direct contact with said fountain roll and means for adjusting the position of said blade support in a direction substantially transverse to said central axis of said fountain roll, said blade support being movable toward said fountain roll by said adjusting means to a position rendering said camming means inoperative to oppose said means for exerting a resilient force.

8. In an ink fountain for a printing press having a base, an ink reservoir mounted on said b so, a rotatable fountain roll journaled in opposing end Walls of said reservoir, said ink reservoir comprising a blade support adjacent said roll, a single flexible blade mounted on said support with an edge thereof substantially parallel to the central axis of said roll, said blade extending be yond said support with said edge disposed proximate to the surface of said roll, means for adjusting the position of said blade support in a direction substantially transverse to said central axis, inflatable means mounted on said blade support below and contiguous with said blade along the length thereof for exerting a variable resilient force urging said edge of said blade along the length thereof into direct contact with said fountain roll and means pivotally mounted on said blade support below said blade for selectively applying a non-resilient force counter to said resilient force to offset said resilient force in part whereby a portion of said blade edge is withdrawn from direct contact with said fountain roll.

References Cited in the file of this patent UNITED STATES PATENTS 

2. IN AN INK FOUNTAIN FOR A PRINTING PRESS HAVING A ROTATABLE FOUNTAIN ROLL, AN INK RESERVOIR COMPRISING A BLADE SUPPORT LOCATED ADJACENT SAID FOUNTAIN ROLL, A SINGLE FLEXIBLE BLADE MOUNTED ON SAID SUPPORT WITH AN EDGE OF SAID BLADE PARALLEL TO AND CLOSELY SPACED FROM THE SURFACE OF SAID FOUNTAIN ROLL, MEANS MOUNTED BELOW SAID BLADE ON SAID SUPPORT FOR EXERTING A VARIABLE YIELDABLE FORCE URGING SAID EDGE OF SAID BLADE ALONG THE LENGTH THEREOF INTO ENGAGEMENT WITH SAID SURFACE OF SAID FOUNTAIN ROLL LENGTHWISE THEREOF AND MEANS MOUNTED BELOW SAID BLADE ON SAID SUPPORT FOR APPLYING A NON-YIELDABLE COUNTERFORCE TO OFFSET SAID YIELDABLE FORCE IN PART AT A POSITION ALONG THE LENGTH OF SAID BLADE TO SELECTIVELY WITHDRAW THE PORTION OF SAID BLADE EDGE ADJACENT SAID POSITION FROM CONTACT WITH SAID FOUNTAIN ROLL. 